You can make your Windows 7 installer no longer have a specific version set as the default version. Upon doing this, you will then be prompted to install any edition of Windows 7. Simply choose the version you wish to install, and you're good to go.
This is because all Windows 7 DVDs actually contain all versions of Windows 7:
- Home Basic
- Home Premium
Although your installer is now universal (all in one – AIO), your product key is not. You will still need to choose the edition you own. You cannot activate different versions of Windows 7 with your original key.
Now without further fanfare there are 2 ways to go about this:
- In a command prompt type
del X:\sources\ei.cfg, where
Xis your flash drive
- or manually navigate to
\sources\and delete the
ei.cfgfile in a copy of your Windows 7 ISO. You can later burn the modified ISO to DVD or USB at a later time.
Microsoft goes into much more detail at their answers page on this topic – How to create a Universal Windows 7 installation DVD or USB Flash Drive.
Update: I've heard reports from people who download their Windows 7 ISOs from their MSDN or TechNet subscriptions are not able have 2 discs (one for 32-bit and one for 64-bit). Your mileage may vary. If you like backing up your official ISOs like I do, let me know if this is actually the case.
That's how to install any edition of Windows 7. If you want to see what installing Windows 7 looks like, head over to that blog post.